1. Field of the Invention
In my U.S. Pat. No. 4,707,962 I disclosed an anchoring system for so-called "cascade" wall structures and the like consisting primarily of a pair of anchor members of more or less "dumbbell-shaped" cross section each having a web section terminating at both ends in an integrally-formed rib or flange and a generally arcuate bridging member, the opposite ends of which lock in behind a transversely-spaced pair of the anchor member flanges while the webs and remaining flanges of the latter are embedded in the soil forming the embankment or wall which must be confined. While this system is far superior in most respects to other prior art systems for the same purpose, it does have certain shortcomings which have proven to be somewhat troublesome and limit its utility, especially in certain applications.
To begin with, the anchor members are quite large, heavy and very difficult for one person to handle. This fact alone creates alignment problems, makes them difficult to stack and store, and they provide no versatility in terms of the distance separating the flanges which is fixed despite the fact that many applications exist in the field in where this spacing is far from ideal.
The flush arrangement of the web and buried portion of the anchor with respect to the top of the embankment creates compaction problems in that heavy equipment cannot be used for backfilling and the contractor is essentially forced to do it by hand. Also, being fabricated of concrete, even reinforced concrete, the tension loads that the web is capable of safely withstanding is somewhat limited.
Furthermore, inasmuch as the web comprises an integral part of the anchor member, auxiliary rods and pipes must be used to align and maintain the flanges in vertically-stacked relation where required.
2. Description of the Related Art
The most pertinent prior art known to me is found in my U.S. patent mentioned above although I have another Pat. No. 4,050,254 which pertains generally to the subject of tied-back retaining wall structures but ones of considerably different construction.
Of the prior art cited in my earlier patent discussed above, I consider to Knight the U.S. Pat. No. 1,847,655 and the German Pat. No. 812463 to be worth noting in terms of the evolution of the art of modular retaining wall structures and because they include certain specific features which I, too, incorporate into my anchoring system. Knight, for example, discloses a wall-forming module having oppositely-facing keyslots in its ends which, upon being placed in opposed face-to-face relation with the keyslot in another such module overlapping the latter, can be connected together by means of a key to form an essentially water-tight joint. This patent, however, includes no tie-back feature by means of which the modules are anchored to the soil nor is one needed since the function of the wall thus formed is not that of a retaining wall at all but rather a piling to be driven into the ground and, therefore, it is already supported both front and back and requires no additional anchoring.
In the German patent, on the other hand, a retaining wall structure is shown in FIGS. 2 and 3 wherein opposed pairs of post-like members are connected together by some sort of anchoring member h and adjacent pairs of these posts are bridged by arcuate panels not unlike those of my earlier patent to form a retaining wall. The posts are devoid of keyslots and there is no suggestion that the anchoring members h could be wire mesh nor is any way shown or suggested for connecting these anchoring elements to the posts. Moreover, nothing in this patent suggests the novel feature of using the mesh in vertically-disposed relation as the sole anchoring member requiring no second post on the other end thereof.